In a speech introducing his economic plan, presidential candidate Rick Perry alleged that "liberals myopically ignore the realities of human nature." He was using this accusation to challenge the liberal idea that raising taxes will increase revenue. But the phrase also tapped into an underlying current of political philosophy — the debate about human nature and its implications for public policy.

Conservatives express skepticism about human nature and attempts to engineer society, while liberals affirm humanity's ability to progress economically, socially and politically. This dichotomy, trumpeted by the prevailing political ideologies of our day, belies the complexity of the human spirit.

Holy writ from diverse traditions acknowledges within the human soul both the natural man and the divine nature. The God of the Hebrew Bible has made man "but little lower than the angels," while lamenting that the thoughts of man's heart are "only evil continually." Early Confucian scholars Xunzi and Mengzi describe human nature as both crooked wood to be straightened and a sprouting seed to be nurtured. The New Testament suggests that although we are "by nature the children of wrath," we can also become "partakers of the divine nature."

These writings recognize the fundamental paradox of humanity: Within each of us strives simultaneously the love of power and the power of love. People are both egoistic and altruistic, idle and industrious, treacherous and trustworthy.

Nowhere do these contradictions manifest themselves more clearly than in the ongoing debate over our national finances. President Obama, Democrats and Republicans in Congress and aspiring presidential candidates alike have outlined competing visions of how best to make the economy grow and the national debt shrink, based in large part on their divergent understandings of how human nature responds to incentives.

The president's jobs plan would have cut payroll taxes to boost the take-home income of middle class workers and extended payouts to the unemployed, while the Senate Democrats' recently unveiled budget blueprint advocates $2 trillion of spending cuts combined with $1 trillion of tax increases. Republicans balk at these proposals, contending that payroll tax cuts stimulate short-term consumption rather than long-term growth, unemployment insurance creates dependency and any tax increases whatsoever will prove counterproductive to economic growth.

Instead, the House GOP's economic proposal emphasizes tax reform and reducing the regulatory burden to stimulate private-sector investment. Among the Republican presidential field, Perry has suggested an optional semi-flat tax of 20 percent; Jon Huntsman has proposed eliminating all personal and corporate deductions; and Herman Cain has called for a new tax code with 9 percent income, corporate and national sales taxes. Democrats cringe at such plans, arguing that they place a disproportionate burden on the poor and middle class and that many wealthy people themselves believe they should be paying higher taxes.

The prevailing political rhetoric often insists that one approach is right, while the other is wrong. However, viewed through the lens of our complex human nature, both conservative and liberal ideas about governance have merit.

An awareness of the natural man should imbue us with humility for the role that political institutions can play in addressing society's challenges. Oftentimes, our baser human characteristics can be magnified in governmental processes, resulting in corruption, inefficiency, and the unintended consequences that arise from the presumption of knowledge.

At the same time, a recognition of our divine nature should give us cautious hope for the progress that can be made through collective political action. Equipped with a government that is "of the people, by the people, for the people," we as Americans would be morally remiss to refrain from using the tools at our disposal to make a difference in issues that individuals, families and churches alone cannot resolve.

Faced with the natural man, proposals that treat government action as a panacea for addressing society's challenges place their hopes in a false and ultimately disappointing god. But in light of the divine nature, attempts to measure any policy solely by the yardstick of "the less government, the better" are morally dubious in their lack of civic compassion.

Instead of aligning ourselves with one of these political ideologies, we should be willing to listen to all viewpoints and consider them on their merits, regardless of the labels attached to them or the party proposing them. And we should acknowledge that just as the realities of human nature require us to be both humble and hopeful, the realities of democratic politics require empathy and compromise.

Rachel Esplin Odell is a research analyst in the Asia Program at the Carnegie Endowment for International Peace and a leader of Generation-H D.C., a grassroots group working to elect Jon Huntsman president in 2012.